[PATCH v4 0/2] blktests: use patient module remover

[Luis Chamberlain <mcgrof@kernel.org>]

This rebases the patient module remover series onto the current blktests
tree and addresses all the feedback from v3 from a long time ago [0]. This
came up recently as Swarna noticed the same flaky bug and I got reminded
to re-send a new iteraiton.

We now have the modprobe --wait upstream so use that if avaiable.

The patient module remover addresses race conditions where module removal
can fail due to userspace temporarily bumping the refcount (e.g., via
blkdev_open() calls). If your version of kmod supports modprobe --wait,
we use that. Otherwise we implement our own patient module remover.

[0] https://lore.kernel.org/all/20221220235324.1445248-2-mcgrof@kernel.org/T/#u

Changes in v4:
  - Rebased onto current blktests master
  - Fixed built-in module handling: _patient_rmmod() now checks for
    the existence of /sys/module/$module_sys/refcnt to detect built-in
    modules and returns success early (Shinichiro Kawasaki)
  - Fixed timeout parameter timing issue: MODPROBE_PATIENT_RM_TIMEOUT_SECONDS
    is now evaluated dynamically inside _patient_rmmod() rather than at
    source time, allowing tests to override the timeout value
    (Shinichiro Kawasaki)
  - Preserved SKIP_REASONS logic in _init_null_blk() when modprobe fails,
    so tests requiring loadable modules are properly skipped rather than
    failing (Shinichiro Kawasaki)
  - Fixed typo in comment: "modprobe -p" -> "modprobe --wait"
    (Luis Chamberlain)
  - Fixed path reference bug: used $module_sys instead of $module for
    /sys/module path checks (Luis Chamberlain)
  - Combined nested while conditions for cleaner code style
    (Shinichiro Kawasaki)
  - Removed redundant $module printing in error messages
    (Shinichiro Kawasaki)
  - Updated to use --wait=TIMEOUT_MSEC syntax (with =) to match the
    upstream kmod implementation


Luis Chamberlain (2):
  blktests: replace module removal with patient module removal
  tests/srp/rc: replace module removal with patient module removal

 common/multipath-over-rdma |  11 +---
 common/null_blk            |   6 +-
 common/nvme                |   9 +--
 common/rc                  | 126 +++++++++++++++++++++++++++++++++++++
 common/scsi_debug          |  14 ++---
 tests/srp/rc               |  19 ++----
 6 files changed, 148 insertions(+), 37 deletions(-)

-- 
2.51.0